Role of the pair of internal and external donors in magnesium chloride-supported Ziegler-Natta catalysts

1991 ◽  
Vol 24 (26) ◽  
pp. 6823-6826 ◽  
Author(s):  
Maria Carmela Sacchi ◽  
Incoronata Tritto ◽  
Chengji Shan ◽  
Raniero Mendichi ◽  
Luciano Noristi
Keyword(s):  
Magnesium Chloride ◽  
Ziegler Natta Catalysts

The role of magnesium chloride as support for Ziegler-Natta catalysts

Polimery ◽  
2000 ◽  
Vol 45 (09) ◽  
pp. 608-613
Author(s):  
KRYSTYNA CZAJA ◽  
MARZENA BIALEK
Keyword(s):  
Magnesium Chloride ◽  
Ziegler Natta Catalysts

Magnesium Chloride is an Effective Therapeutic Agent for Prostate Cancer

2018 ◽  
Vol 8 (1) ◽  
pp. 62 ◽  
Author(s):  
Julianna Maria Santos ◽  
Fazle Hussain
Keyword(s):  
Prostate Cancer ◽  
Magnesium Chloride ◽  
Epithelial Mesenchymal Transition ◽  
Chromatin Condensation ◽  
Myosin Ii ◽  
In Vivo Studies ◽  
Migration Speed ◽  
Mesenchymal Transition

Background: Reduced levels of magnesium can cause several diseases and increase cancer risk. Motivated by magnesium chloride’s (MgCl2) non-toxicity, physiological importance, and beneficial clinical applications, we studied its action mechanism and possible mechanical, molecular, and physiological effects in prostate cancer with different metastatic potentials.Methods: We examined the effects of MgCl2, after 24 and 48 hours, on apoptosis, cell migration, expression of epithelial mesenchymal transition (EMT) markers, and V-H+-ATPase, myosin II (NMII) and the transcription factor NF Kappa B (NFkB) expressions.Results: MgCl2 induces apoptosis, and significantly decreases migration speed in cancer cells with different metastatic potentials.  MgCl2 reduces the expression of V-H+-ATPase and myosin II that facilitates invasion and metastasis, suppresses the expression of vimentin and increases expression of E-cadherin, suggesting a role of MgCl2 in reversing the EMT. MgCl2 also significantly increases the chromatin condensation and decreases NFkB expression.Conclusions: These results suggest a promising preventive and therapeutic role of MgCl2 for prostate cancer. Further studies should explore extending MgCl2 therapy to in vivo studies and other cancer types.Keywords: Magnesium chloride, prostate cancer, migration speed, V-H+-ATPase, and EMT.

Crystalline magnesium chloride–electron donor complexes: new support materials for Ziegler–Natta catalysts

2017 ◽  
Vol 46 (13) ◽  
pp. 4452-4460 ◽  
Author(s):  
V. H. Nissinen ◽  
I. O. Koshevoy ◽  
T. T. Pakkanen
Keyword(s):  
Crystal Structure ◽  
Structure Formation ◽  
Magnesium Chloride ◽  
Donor Ligands ◽  
Nitrogen Donor Ligands ◽  
Support Materials ◽  
Polymerization Catalyst ◽  
Nitrogen Donor ◽  
Crystal Structure Formation ◽  
Ziegler Natta Catalysts

Chelating oxygen and nitrogen donor ligands (1,2-dimethoxyethane, 1,3-dimethoxypropane, and N,N′-diethylethylenediamine) are found to dictate the crystal structure formation of MgCl2, the important support component of a polymerization catalyst.

scholarly journals The role of bound potassium ions in the hydrolysis of low concentrations of adenosine triphosphate by preparations of membrane fragments from ox brain cerebral cortex

1970 ◽  
Vol 120 (1) ◽  
pp. 15-24 ◽  
Author(s):  
P. S. G. Goldfarb ◽  
R. Rodnight
Keyword(s):  
Potassium Chloride ◽  
Magnesium Chloride ◽  
Adenosine Triphosphatase ◽  
Time Course ◽  
Atp Hydrolysis ◽  
Protein Ratio ◽  
Low Concentrations ◽  
Hydrolysis Of ◽  
Emission Flame

1. The intrinsic Na+, K+, Mg2+ and Ca2+ contents of a preparation of membrane fragments from ox brain were determined by emission flame photometry. 2. Centrifugal washing of the preparation with imidazole-buffered EDTA solutions decreased the bound Na+ from 90±20 to 24±12, the bound K+ from 27±3 to 7±2, the bound Mg2+ from 20±2 to 3±1 and the bound calcium from 8±1 to <1nmol/mg of protein. 3. The activities of the Na++K++Mg2+-stimulated adenosine triphosphatase and the Na+-dependent reaction forming bound phosphate were compared in the unwashed and washed preparations at an ATP concentration of 2.5μm (ATP/protein ratio 12.5pmol/μg). 4. The Na+-dependent hydrolysis of ATP as well as the plateau concentration of bound phosphate and the rate of dephosphorylation were decreased in the washed preparation. The time-course of formation and decline of bound phosphate was fully restored by the addition of 2.5μm-magnesium chloride and 2μm-potassium chloride. Addition of 2.5μm-magnesium chloride alone fully restored the plateau concentration of bound phosphate, but the rate of dephosphorylation was only slightly increased. Na+-dependent ATP hydrolysis was partly restored with 2.5μm-magnesium chloride; addition of K+ in the range 2–10μm-potassium chloride then further restored hydrolysis but not to the control rate. 5. Pretreatment of the washed preparation at 0°C with 0.5nmol of K+/mg of protein so that the final added K+ in the reaction mixture was 0.1μm restored the Na+-dependent hydrolysis of ATP and the time-course of the reaction forming bound phosphate. 6. The binding of [42K]potassium chloride by the washed membrane preparation was examined. Binding in a solution containing 10nmol of K+/mg of protein was linear over a period of 20min and was inhibited by Na+. Half-maximal inhibition of 42K+-binding required a 100-fold excess of sodium chloride. 7. It was concluded (a) that a significant fraction of the apparent Na+-dependent hydrolysis of ATP observed in the unwashed preparation is due to activation by bound K+ and Mg2+ of the Na++K++Mg2+-stimulated adenosine triphosphatase system and (b) that the enzyme system is able to bind K+ from a solution of 0.5μm-potassium chloride.

Spectroscopic Investigation of Heterogeneous Ziegler-Natta Catalysts: Ti and Mg Chloride Tetrahydrofuranates, Their Interaction Compound, and the Role of the Activator

2011 ◽  
Vol 17 (31) ◽  
pp. 8648-8656 ◽  
Author(s):  
Kalaivani Seenivasan ◽  
Anna Sommazzi ◽  
Francesca Bonino ◽  
Silvia Bordiga ◽  
Elena Groppo
Keyword(s):  
Spectroscopic Investigation ◽  
Ziegler Natta Catalysts

Activation effect of alkoxysilanes as external donors in magnesium chloride-supported Ziegler-Natta catalysts

1992 ◽  
Vol 25 (22) ◽  
pp. 5914-5918 ◽  
Author(s):  
Maria Carmela Sacchi ◽  
Fabrizio Forlini ◽  
Incoronata Tritto ◽  
Raniero Mendichi ◽  
Giulio Zannoni ◽  
...  
Keyword(s):  
Magnesium Chloride ◽  
Activation Effect ◽  
Ziegler Natta Catalysts

Microstructure Distribution of Polypropylenes Obtained in the Presence of Traditional Phthalate/Silane and Novel Diether Donors:  A Tool for Understanding the Role of Electron Donors in MgCl2-Supported Ziegler−Natta Catalysts

1996 ◽  
Vol 29 (18) ◽  
pp. 5770-5776 ◽  
Author(s):  
Giampiero Morini ◽  
Enrico Albizzati ◽  
Giulio Balbontin ◽  
Ines Mingozzi ◽  
Maria Carmela Sacchi ◽  
...  
Keyword(s):  
Electron Donors ◽  
Ziegler Natta Catalysts

scholarly journals Copolymerization of ethylene and propylene catalyzed by magnesium chloride supported vanadium/titanium bimetallic Ziegler-Natta catalysts

2011 ◽  
Vol 29 (4) ◽  
pp. 475-482 ◽  
Author(s):  
Tao Jiang ◽  
Hong-xia Chen ◽  
Chen-gang Cao ◽  
Guo-liang Mao ◽  
Wei Du ◽  
...  
Keyword(s):  
Magnesium Chloride ◽  
Vanadium Titanium ◽  
Ziegler Natta Catalysts
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